A board incorporated in so-called IT (Information Technology) devices such as servers and network equipment is generally referred to as “motherboard,” and a plurality of communication modules are connected to such a motherboard.
Here, to achieve higher performance and further reduced power consumption of an IT device and the like, it is necessary to further miniaturize each communication module and mount as many communication modules as possible on a housing panel (front panel or rear panel) of the IT device and the like. More specifically, it is necessary to reduce the width of each communication module so that a plurality of communication modules are mounted on a housing panel of a given size at high density.
One method of reducing the width of the communication module is to reduce the pitch of electrodes formed on a connector connecting the motherboard to the communication module. This connector has been conventionally known as a two-piece structure connector composed of a male connector (plug connector) and a female connector (receptacle connector) and having electrodes arranged at a narrow pitch.
When the two-piece structure connector is used to connect the communication module to the motherboard, the communication module is provided with the plug connector while the motherboard is provided with the receptacle connector in many cases. Also, the communication module may be provided with a card edge type connector. This is because the card edge type connector is suitable for providing a plurality of electrodes having stable quality at low cost. The card edge type connector, however, has low accuracy and is therefore unsuitable for reducing the pitch of electrodes (see, e.g., Japanese Patent Application Laid-Open Publication. No. 2013-84577 (Patent Document 1)).